This invention relates to firearms, and in particular, to a firearm having a closed breech electrically switched ignition system.
Firearms which are loaded through their barrels with quick-burning, powder-type propellants are commonly referred to as muzzleloaders. Muzzleloaders are typically used by hunters during special xe2x80x9cmuzzleloadingxe2x80x9d hunting seasons where use of modern center-fire firearms or like rifles is prohibited. Commonly known designs include match-lock, wheel-lock, flint-lock, and percussion muzzleloaders, which are distinguished by their ignition mechanisms.
As shown in FIG. 4, a conventional muzzleloader typically includes a barrel 60, the breech of which defines a combustion chamber 62, a breech plug 64 enclosing the breech of the barrel 60, a vent 66 disposed in the wall of the barrel 60 (or breech plug), an ignition system constructed with a percussion nipple 68 (or a flint and striker mechanism), and a hammer and trigger arrangement 74. The muzzleloader is operated by pouring a finite amount of powdered propellant 71 down the forward end of the barrel 60. A projectile, such as a slug or ball, is then inserted into the barrel 60 and pushed down onto the propellant 71. The muzzleloader must then be primed. Muzzleloaders with percussion nipple ignition systems as shown in FIG. 4, are primed by placing a percussion cap 70 on the percussion nipple 68. Muzzleloaders with flint and striker mechanisms are primed by placing propellant in a pan structure of the flint and striker mechanism. After priming, the muzzleloader is fired by cocking the hammer and then pulling the trigger. In percussion nipple ignition systems, the hammer 75 strikes the percussion cap 70 which contains a small amount of propellant 73 that ignites on impact, producing a hot flame of gas. This hot flame of gas travels through the nipple 68 and vent 66 to ignite the propellant 71 in the combustion chamber 62. In flint and striker ignition systems, the hammer contains flint which strikes a steel bar, thus creating a spark which ignites the propellant in the pan. The propellant in the pan bums rapidly, creating a flame and gas which travel through the vent and ignite the propellant in the combustion chamber. Upon ignition with either system, the propellant 71 in the breech burns quickly, building high pressures which accelerate the projectile 72 rapidly down the barrel 60 toward a target.
Unfortunately, conventional ignition systems used on muzzleloaders lessen their accuracy, are not always reliable, are slow to reload, and produce less firepower than center-fire rifles. The reduced accuracy results from undesirably long xe2x80x9clock-timesxe2x80x9d. Lock-time is a time period which is measured from when the trigger is pulled until the projectile exits the barrel. Long lock times reduce shooting accuracy because the firearm has more time to vibrate and drift off the target after the trigger is pulled. The lock-times of conventional muzzleloader ignition systems are excessive because it takes a relatively long period of time for the flame and gas to travel through the vent to ignite the propellant. Typical muzzleloaders have lock-times that range from about 20 milliseconds to about 50 milliseconds. For comparison, a modern center-fire rifle has a lock-time of approximately 15 milliseconds.
Accuracy is also reduced by the vent which permits the gases generated by the propellant charge in the breech to escape therefrom into the air. The venting of gases lowers breech pressure which in turn, reduces projectile velocity. The reduced projectile velocity lessen the muzzleloader""s accuracy because wind drift has more time to alter the trajectory of the projectile before it reaches the target.
Conventional ignition systems used on muzzleloaders are also slow to reload because each shot requires recharging of the priming system either with propellant or a cap. Repriming takes time and manual dexterity and caps can be lost or propellant spilled when priming under stressful conditions, thus delaying the time to fire.
A further disadvantage of these ignition systems is that the cap or propellant is susceptible to contamination from water, particularly rain or human contact, resulting in unreliable ignition. Many misfires are caused by caps or propellant which have been contaminated with water from rainy conditions. The vent also allows moisture to seep through its mechanical joints into the propellant in the combustion chamber which can result in poor ignition even if the cap operates properly.
The vent causes other ignition problems as well. In particular, the vent hole is susceptible to particle contamination from the cap, hunter, or propellant itself due to small diameter of the vent""s orifice which limits the gases escaping from vent. If the vent orifice becomes plugged, the gases from the cap will not hit the propellant, and the muzzleloader will not fire.
Accordingly, there a need for muzzleloaders with improved ignition systems which provide increased accuracy, ignition reliability, faster reloading, and increased firepower.
A firearm comprises a barrel having a combustion chamber for receiving propellant and at least one projectile. Electrically switched propellant igniting means are provided within the chamber for igniting propellant dispensed into the combustion chamber. Trigger switching means, electrically coupled to the igniting means, apply an electrical current pulse to the igniting means when the trigger means is operated in a firing mode, the pulse having a duration which causes the igniting means to ignite propellant dispensed into the combustion chamber.